Solar urticaria are the development of urticarial lesions in response to ultraviolet or visible light.
The etiology is unknown.
Urticaria develop in light exposed skin within minutes of exposure.
- Definition of the offending wave lengths is important if they are to be avoided. Testing with a monochromator attached to a broad spectrum light source will allow for the correct determination of the offending wavelengths. Knowing the wavelengths will allow for the appropriate sunblock to be recommended.
- Solar urticaria should be differentiated from other physical urticarias that might be induced by heat or pressure, rather than light.
- Patients with solar urticaria may spontaneously recover.
- H1 antihistamines may be useful, as can desensitization with chronic low doses of light.